Use the down key when on an image to go into the image actions toolbar. While there, left and right will let you jump between the actions and space will trigger them. Use the up key to place the focus on the image again.

When modal windows are opened, it automatically focuses on the first focusable element in that modal. As the fields autosave, just tab out of a field to let it blur and save. Use enter to select a tag from the dropdown, or to create a new one based on what you typed.

Closing modals is done with esc or by focusing on the X button and triggering with space. After closing the modal, focus goes back to what was last focused.